This invention relates generally to mechanisms for securing tubes to tube connectors. More particularly, the invention relates to tube securing mechanisms for use in respirators.
A respirator or ventilator provides a regulated flow of breathing gas to a patient, typically during inhalation therapy, which may be administered for a variety of reasons. A respirator uses a system of tubes, referred to as the patient breathing circuit, to direct the flow of gas to and from the patient's lungs. Gas supplied to the patient may also pass through a humidifier, which typically both heats and humidifies the gas, and some of the added moisture will usually condense out from the gas after it leaves the humidifier. This humidifier action, together with the heat and moisture derived from the patient's lungs, provides a warm and humid environment for the tubes of the patient breathing circuit.
The tubes are usually made of polyethylene or a similar flexible material, and the various tube connectors and fittings are of a more rigid plastic material. Securing tubes to their connectors and fittings in warm and moist conditions has proved to be a significant problem in the design and operation of respirators. Typically, tubes are manufactured with an end portion that includes an annular groove, which engages with a corresponding ridge or flange on the fitting. Frequently, however, such arrangements that work perfectly well under cool, dry conditions are impractical or unreliable in warm moist conditions. Warm temperatures and the presence of moisture render the polyethylene tube material both more pliable and more slippery in contact with the tube connectors. As a result, tubes can sometimes be removed from their fittings inadvertently. There has therefore been a significant need for a respirator tube securing mechanism that operates reliably under moist and warm conditions. Ideally, such a mechanism must also be simple to operate and relatively inexpensive to manufacture, since both the tubes and their securing mechanisms may be produced as disposable items. The present invention satisfies all these needs.